初始化windows窗口

 LRESULT WINAPI WndProc(HWND hWnd,UINT msg,WPARAM wParam,LPARAM lParam)
 {
     PAINTSTRUCT ps;
     switch (msg)
     {
     case WM_PAINT:
         {
             BeginPaint(hWnd,&ps);
             EndPaint(hWnd,&ps);
             return ;
         }
     case WM_DESTROY:
         {
             PostQuitMessage();
             return ;
         }
     }
 
     return DefWindowProc(hWnd,msg,wParam,lParam);
 }
 void initWndClass(HINSTANCE hInstance,WNDCLASSEX &wndClass)
 {
     wndClass.cbSize = sizeof(WNDCLASSEX);
     wndClass.style = CS_HREDRAW | CS_VREDRAW;
     wndClass.lpfnWndProc = WndProc;
     wndClass.cbClsExtra = ;
     wndClass.cbWndExtra = ;
     wndClass.hInstance = hInstance;
     wndClass.hIcon = LoadIcon(NULL,IDI_APPLICATION);
     wndClass.hCursor = LoadCursor(NULL,IDC_ARROW);
     wndClass.hbrBackground = (HBRUSH)GetStockObject(GRAY_BRUSH);
     wndClass.lpszClassName = TEXT(CLASSNAME);
     wndClass.lpszMenuName = NULL;
     wndClass.hIconSm = LoadIcon(NULL,IDI_WINLOGO);
 }

 int WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,LPSTR lpCmdLine,int nShowCmd)
 {
     HWND hWnd;
 
     WNDCLASSEX wndClass;
     initWndClass(hInstance,wndClass);
 
     RegisterClassEx(&wndClass);
 
     hWnd = CreateWindow(
         TEXT(CLASSNAME),
         TEXT(APPNAME),
         WS_OVERLAPPEDWINDOW,
         CW_USEDEFAULT,
         CW_USEDEFAULT,
         SCREEN_W,
         SCREEN_H,
         NULL,
         NULL,
         hInstance,
         NULL
         );
 
     if (NULL == hWnd)
     {
         MessageBox(NULL,TEXT("NULL == hWnd"),NULL,MB_OK);
         return ;
     }
 
     UpdateWindow(hWnd);
     ShowWindow(hWnd,nShowCmd);
     MSG msg;
     while (true)
     {
         if ( PeekMessage(&msg,NULL,,,PM_REMOVE) )
         {
             if (WM_QUIT == msg.message)
             {
                 break;
             }
             TranslateMessage(&msg);
             DispatchMessage(&msg);
         }
         else
         {
             Render();
         }
     }
     Release();
     return msg.lParam;
 }